Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Calcular a tarifa média para viagens entre cada par de estações na Linha Laranja
 ###Tabelas: 
CREATE TABLE stations (station_id INT, station_name VARCHAR(255), line VARCHAR(255));CREATE TABLE trips (trip_id INT, start_station_id INT, end_station_id INT, fare FLOAT); INSERT INTO stations (station_id, station_name, line) VALUES (1, 'North Station', 'Orange Line'), (2, 'Back Bay', 'Orange Line'), (3, 'Forest Hills', 'Orange Line'); INSERT INTO trips (trip_id, start_station_id, end_station_id, fare) VALUES (1, 1, 2, 2.5), (2, 2, 1, 3.0), (3, 3, 2, 1.5);
SELECT s1.station_name as start_station, s2.station_name as end_station, AVG(t.fare) as avg_fare FROM trips t JOIN stations s1 ON t.start_station_id = s1.station_id JOIN stations s2 ON t.end_station_id = s2.station_id WHERE s1.line = 'Orange Line' AND s2.line = 'Orange Line' GROUP BY s1.station_name, s2.station_name;